Multiple electronic equipment units are often housed in high-density assemblies, such as server racks, in which modular electronic equipment units (e.g., servers) are mounted on an upright frame or rack in a vertically spaced, stacked arrangement. Large numbers of such server racks, for example, may in turn be housed together in a high-density electronic equipment facility or data center.
Electronic equipment generates heat, typically requiring cooling to prevent overheating. The importance of heat management is amplified when electronic equipment is located in concentrated density, for example, server racks and data centers. Data center cooling systems often include air cooling of individual modular components (e.g., rack servers), for example by circulating air through the casings of respective rack-mounted servers. Such air cooling, however, can lead to inefficient data center architecture and may expose internal components of the servers to outside contamination in instances where ambient air is used.
Alternatively, or in combination with air cooling, heat rejection of rack-mounted server components can be achieved by direct liquid cooling, for example by circulating a liquid coolant along sealed conduits that pass through the server casings in heat exchange relationship with server components. A complication of direct liquid cooling is that it necessarily brings liquid coolant into close proximity with liquid-intolerant electronic components, and is thus perceived as exposing the server rack and/or data center to substantial leakage failure risks.